This invention primarily addresses a wireless wide area star topology communication network in which a centrally located hub or access point services a large number of nodes at fixed locations. A typical example of such a communication network is where a single or small number of access points communicate with a very large number of utility meters or Smart Grid nodes distributed across a large metropolitan area.
Currently, a large variety of network structures have been designed for the Smart Grid and other similar applications. The most popular networks operate in one of the shared Industrial, Scientific and Medical (ISM) radio frequency bands and use either a mesh or star topology. Essentially all current networks are based on a single or combination of the Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), or Frequency Division Multiple Access (FDMA) techniques.
One of the biggest challenges of all these networks is how to handle data collisions caused when more than one node attempts to communicate with the central access point at the same TDMA time, on the same FDMA frequency, or using the same CDMA code. Numerous protocols have been developed over the years on how the nodes and access point should respond when collisions occur. Other challenges include how nodes initially acquire and maintain system timing when joining the network.
In solving these problems, the resulting implemented network structure is typically quite rigid in its capabilities. All nodes tend to be limited to approximately the same data rate and range performance and that performance may decrease as additional users are added. This is a major handicap in that once the network is designed and installed, it is not possible to easily upgrade or change its performance.
Accordingly, it is the object of the present invention to disclose methods and apparatus which provide a new and improved wireless network structure that solves these and other problems and allows the data rate of each node to be programmable. This feature allows each node to be matched to the communication needs required at its location and allows a single network to service many different communication requirements of a utility or other user. Currently, multiple different systems are typically required to service these varying requirements.